Expected patterns of blood test results during fasting and after mixed meal testing (if plasma glucose <3.0 mmol/L or 55 mg/dL) in normal and pathologic hypoglycemia states

Table 6.2-3. Expected patterns of blood test results during fasting and after mixed meal testing (if plasma glucose <3.0 mmol/L or 55 mg/dL) in normal and pathologic hypoglycemia states
Clinical state	Signs/symptoms	Insulina	C-peptidea	Proinsulina	Beta-HBa	Glucose response to glucagona	OHA	Autoantibodies
Normal	–	<	<	<	≥	<	–	–
Excess exogenous insulin	√	≥	<	<	<	≥	–	–
Excess sulfonylurea/meglitinide	√	≥	≥	≥	<	≥	√	–
Insulinoma, NIPHS, PGBH	√	≥	≥	≥	<	≥	–	–
Insulin autoimmune syndrome	√	≥	≥	≥	<	≥	–	√ (to insulin)
Insulin receptor autoimmune syndrome	√	<	<	<	<	≥	–	√ (to insulin receptor)
IGF-2-secreting tumorb	√	<	<	<	<	≥	–	–
a The symbols represent expected blood test results relative to the normal value or threshold as follows: – Insulin: 21 pmol/L or 3 microIU/mL. – C-peptide: 200 pmol/L or 0.6 ng/mL. – Proinsulin: 5 pmol/L. – Beta-HB: 2.7 mmol/L. – Glucose response to glucagon: 1.4 mmol/L or 25 mg/dL. b Additionally expect increased pro-IGF-2, free IGF-2, and IGF-2/IGF-1 ratio.
Adapted from Journal of Clinical Endocrinology & Metabolism, March 2009, 94(3): 709-728.
–, absent; √, present; beta-HB, beta-hydroxybutyrate; IGF, insulin-like growth factor; NIPHS, noninsulinoma pancreatogenous hypoglycemia syndrome; OHA, oral hypoglycemic agent; PGHB, post–gastric bypass hypoglycemia.